olds 307 and 403

I am really considering boring my 350 and using Probe forged pistons. I would use ARP bolts and resize. The 330 crank was balanced with 18cc Speed Pro forged pistons and factory rods. I sold the pistons and rods. I will have 350 and 403 rods to use. Do the added weight of 403 rods negate the benefits in a 350? I will be maybe using nitrous. The Probe pistons are considerbly lighter and have a taller compression height. The crank looks good to go as is, would just need cleaned and balanced. I have kept the journals oiled in my shop.

380 Racer

I always used stock 350 rods and the only problem I ever had was when it dropped a valve and turned one into a Z shape. All were used to 6200 repeatedly. Never used giggle gas tho.

It has been pounded into my head "lighter is better". I feel the SB rods are fairly strong. How much does each weigh?

Run to Rund

Check the cost of rebuilding with new ARP bolts vs. aftermarket rods. For a BBO, it is about as cheap to get new rods. Also, the load on the rods is much less with modern light pistons and pins.

380 Racer

I agree, the heavier 403 rod is used because of the big-*** pistons, but how much stronger? I sure don't know.

cutlassefi

The stock 350 rod is more than adequate for most builds.

olds 307 and 403

Even Bill Travato who hates them, said 400 hp in his book. Sounds decent to me. I will price out reworking rods vs the sbc set ups.

cutlassefi

You'll have to factor in that your Probe pistons have Olds pins. Now if you go with sbc rods you'll need to open up the pin end.

Run to Rund

How high do you want to rev, meaning how big a camshaft? For regular over 6000 excursions, I suggest pistons and pins for SBC because the pins are lighter, and buy rods for SBC. Cut the crank to fit.

jfb

this is a quote from a major engine rebuilder and i personally would not push something to a breaking point. 500 flywheel horsepower for factory rods or 400 at the wheels. I always build things at least 10 to 15 percent stronger for playing room or error room.

380 Racer

If a rod manufacturer puts a HP rating on a set of rods, you can bet your butt that rating is very under-rated plain and simple.

captjim

Not only that, but it takes a LOT of cam and cylinder head to get an honest 500 HP out of a 350. Stock rods with .0025 clearance and ARP bolts will be fine.

olds 307 and 403

I think they will do just fine. I think sticking with my stock pistons is the route I will go. Pretty sure I will buy bare Pro Comp heads. I will mill them to 65cc. That will give me 9 to 1 on the 350, 10 to 1 on the 403 stroker. I am thinking the Lunati high efficiency 207/207 .461/.461 on 112 lsa. I will get matching springs and 1.7 roller rockers. 2200-2500 stall on the 4L60E and 700 cfm high flow tbi with the stock sbc 350 computer.